Novel Peptide Phoenixin Acts as a "Eat More" Signal After Feeding in Fish

Phoenixin peptide in goldfish promotes feeding as a feedforward signal — eating triggers PNX expression which stimulates more food intake.

Qin, Xiangfeng et al.·Frontiers in endocrinology·2025·lowAnimal StudyAnimal Study
RPEP-13146Animal Studylow2025RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Animal Study
Evidence
low
Sample
N=Not specified (animal study)
Participants
Goldfish

What This Study Found

Phoenixin acts as a feedforward appetite signal in goldfish — feeding increases PNX expression, which in turn stimulates additional food intake.

Key Numbers

Two PNX isoforms and one GPR173 cloned; both IP and ICV injection of PNX20a/b increased food intake; expression rose after feeding, fell with fasting.

How They Did This

Gene cloning, tissue expression (RT-PCR), phylogenetic analysis, in silico modeling, and feeding experiments in goldfish.

Why This Research Matters

Understanding feedforward appetite signals may explain binge eating mechanisms and could identify new targets for appetite control.

The Bigger Picture

Phoenixin adds to the growing list of appetite-regulating peptides, with a unique feedforward mechanism distinct from hunger/satiety hormones.

What This Study Doesn't Tell Us

Fish model — feedforward mechanisms may differ in mammals. Single species studied.

Questions This Raises

  • ?Does phoenixin play a similar feedforward role in human appetite?
  • ?Could blocking phoenixin help prevent binge eating?

Trust & Context

Key Stat:
Feedforward Feeding itself increases phoenixin expression which stimulates further food intake — a positive feedback loop
Evidence Grade:
Fish model study with comprehensive molecular characterization — novel mechanistic finding but needs mammalian confirmation.
Study Age:
Published in 2025, characterizing phoenixin's role in appetite for the first time in fish.
Original Title:
Goldfish phoenixin: (I) structural characterization, tissue distribution, and novel function as a feedforward signal for feeding-induced food intake in fish model.
Published In:
Frontiers in endocrinology, 16, 1570716 (2025)
Database ID:
RPEP-13146

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / Observational
Case Report / Animal StudyOne case or non-human subjects
This study

Tests effects in animals (usually mice or rats), not humans.

What do these levels mean? →

Frequently Asked Questions

What is phoenixin?

A recently discovered peptide involved in appetite control — in goldfish, eating triggers its release, which stimulates more eating.

Why study appetite in fish?

Fish share conserved appetite-regulating pathways with humans. Discoveries in fish often translate to understanding human appetite and obesity.

Read More on RethinkPeptides

Cite This Study

RPEP-13146·https://rethinkpeptides.com/research/RPEP-13146

APA

Qin, Xiangfeng; Ye, Cheng; Chan, Ying Wai; Wong, Anderson O L. (2025). Goldfish phoenixin: (I) structural characterization, tissue distribution, and novel function as a feedforward signal for feeding-induced food intake in fish model.. Frontiers in endocrinology, 16, 1570716. https://doi.org/10.3389/fendo.2025.1570716

MLA

Qin, Xiangfeng, et al. "Goldfish phoenixin: (I) structural characterization, tissue distribution, and novel function as a feedforward signal for feeding-induced food intake in fish model.." Frontiers in endocrinology, 2025. https://doi.org/10.3389/fendo.2025.1570716

RethinkPeptides

RethinkPeptides Research Database. "Goldfish phoenixin: (I) structural characterization, tissue ..." RPEP-13146. Retrieved from https://rethinkpeptides.com/research/qin-2025-goldfish-phoenixin-i-structural

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkPeptides research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.